1. Field of the Invention
The present invention relates to a tape printing apparatus with a test printing function, the apparatus having a printer that prints predetermined test patterns onto a tape when an appropriate key is operated.
2. Description of the Related Art
Heretofore, word processors and like machines have a test printing function or demonstration printing function designed to print predetermined test patterns upon operation of an appropriate key. The printed test patterns allow the user to know the fonts and ornamented characters that may be printed by the machine.
There also exist tape printing devices such as that disclosed in Japanese Patent Application No. Hei 3-217860. The disclosed tape printing apparatus has a thermal head that prints the characters and other symbols entered from a keyboard onto a tape.
The disclosed tape printing apparatus accommodates any one of five different widths of tapes: 6 mm, 9 mm, 12 mm, 18 mm and 24 mm. The apparatus prints characters and other symbols on tapes of the different widths. In addition, the disclosed apparatus prints fonts of various sizes as well as diversely ornamented characters. However, characters of specific sizes or in particular ornamental styles may not be available for printing on particular tape widths.
As with the word processors, the disclosed tape printing apparatus needs and is provided with the test or demonstration printing function whereby printable character sizes and ornamental styles are verified. The test patterns printed by the test or demonstration printing function include those characters of all sizes and in all ornamental styles that may be printed by the tape printing apparatus.
The above tape printing apparatus is furnished with only one kind of data by which to print the test patterns. The limited amount of the test pattern print data gives rise to one disadvantage of the apparatus. That is, when a wide tape is loaded in the tape printing apparatus, the test patterns are printed thereon without trouble; but when a narrow tape is used for test pattern printing, large-size characters of the printed test patterns can exceed the tape width.
Attempts to print test patterns onto the narrow tape can damage the platen roller of the apparatus. That is, when set to print the test patterns, the apparatus heats up its thermal head while the tape is being pinched between the thermal head and the platen roller made of rubber. With some heating elements of the thermal head coming into direct contact with the platen surface, the rubber platen roller can be burned and damaged.